Treatment strategies for interstitial granulomatous dermatitis: Systematic review and expert opinion.

BACKGROUND: Interstitial granulomatous dermatitis (IGD) is a rare inflammatory dermatosis with heterogeneous clinical presentations and a characteristic granulomatous histopathological pattern. Evidence-based therapeutic recommendations are lacking. OBJECTIVES: To systematically review and synthesize the available evidence on therapeutic strategies for IGD, with emphasis on treatment effectiveness, disease resolution and relapse, and to propose a practice-oriented management approach. METHODS: A systematic review was conducted according to PRISMA guidelines. PubMed/MEDLINE was searched from inception to February 2026. Studies reporting treatment outcomes in patients with histologically confirmed IGD were included. Data on demographics, associated diseases, suspected drug triggers, treatments and clinical outcomes were extracted and analysed descriptively. RESULTS: A total of 108 articles, comprising 182 patients, were included. They were 115 females (63.2%) with a median age of 58 years. The most frequent presentation consisted of plaques, followed by a combination of plaques and papules localized on the axillae, groin and/or the proximal portions of the limbs. Rheumatological or autoimmune diseases represented the most frequent association (in about 50% of patients). A drug-induced aetiology was identified in 33.5% of cases (including cardiovascular drugs, biologic agents and targeted therapies), with drug withdrawal leading to complete or partial resolution in 95.9% of evaluable patients. Haematological and solid tumours were found in 18.4% of cases. Among treatments, topical corticosteroids achieved complete response in 52.2% of cases, while systemic corticosteroids resulted in complete response in 58.3%. Immunomodulatory agents (including hydroxychloroquine, methotrexate and dapsone) showed variable efficacy. TNF-α inhibitors and JAK inhibitors were associated with high response rates in refractory disease. Disease recurrence occurred in 27.0% of patients with available follow-up data. CONCLUSIONS: Optimal management of IGD relies on an aetiology-oriented approach. Withdrawal of causative drugs represents the most effective intervention when applicable. Topical and systemic corticosteroids remain first-line therapies; immunomodulatory and biologic agents are reserved for refractory disease.